CardiacWave

2021 ◽  
Vol 5 (3) ◽  
pp. 1-26
Author(s):  
Chenhan Xu ◽  
Huining Li ◽  
Zhengxiong Li ◽  
Hanbin Zhang ◽  
Aditya Singh Rathore ◽  
...  
Keyword(s):  
Vital Signs ◽  
Cardiac Activity ◽  
Ground Truth ◽  
P Wave ◽  
Qrs Complex ◽  
High Definition ◽  
Full Spectrum ◽  
P Waves ◽  
High Positive Correlation ◽  
Heart Monitoring

Using wireless signals to monitor human vital signs, especially heartbeat information, has been intensively studied in the past decade. This non-contact sensing modality can drive various applications from cardiac health, sleep, and emotion management. Under the circumstance of the COVID-19 pandemic, non-contact heart monitoring receives increasingly market demands. However, existing wireless heart monitoring schemes can only detect limited heart activities, such as heart rate, fiducial points, and Seismocardiography (SCG)-like information. In this paper, we present CardiacWave to enable a non-contact high-definition heart monitoring. CardiacWave can provide a full spectrum of Electrocardiogram (ECG)-like heart activities, including the details of P-wave, T-wave, and QRS complex. Specifically, CardiacWave is built upon the Cardiac-mmWave scattering effect (CaSE), which is a variable frequency response of the cardiac electromagnetic field under the mmWave interrogation. The CardiacWave design consists of a noise-resistant sensing scheme to interrogate CaSE and a cardiac activity profiling module for extracting cardiac electrical activities from the interrogation response. Our experiments show that the CardiacWave-induced ECG measures have a high positive correlation with the heart activity ground truth (i.e., measurements from a medical-grade instrument). The timing difference of P-waves, T-waves, and QRS complex is 0.67%, 0.71%, and 0.49%, respectively, and a mean cardiac event difference is within a delay of 5.3 milliseconds. These results indicate that CaridacWave offers high-fidelity and integral heart clinical characteristics. Furthermore, we evaluate the CardiacWave system with participants under various conditions, including heart and breath rates, ages, and heart habits (e.g., tobacco use).

Electrocardiographic Evaluation in Patients With Spinal Muscular Atrophy: A Case-Control Study

2018 ◽  
Vol 33 (7) ◽  
pp. 487-492 ◽  
Author(s):  
Raffaele Falsaperla ◽  
Giovanna Vitaliti ◽  
Ausilia Desiree Collotta ◽  
Chiara Fiorillo ◽  
Alfredo Pulvirenti ◽  
...  
Keyword(s):  
Heart Rate ◽  
Spinal Muscular Atrophy ◽  
Cardiac Tissue ◽  
Muscular Atrophy ◽  
P Wave ◽  
Cardiac Conduction ◽  
Control Group ◽  
Qrs Complex ◽  
P Waves ◽  
Spinal Muscular Atrophy Type

Background: This study aimed to show the impairment of autonomic cardiac conduction causing bradycardia and/or electrocardiographic alterations in children affected by spinal muscular atrophy type 1 and 2 (SMA 1 and 2). Methods: We included 25 spinal muscular atrophy patients, admitted from November 2016 to May 2017. All patients underwent an electrocardiographic examination and we studied PR and QRS intervals, P-waves and QRS amplitudes, and heart rate in spinal muscular atrophy patients compared to a control group. Results: In all patients, we found longer PRi and QRSi ( P < .05), lower P-wave and QRS complex amplitudes ( P < .01), and a decreased heart rate ( P < .01) with respect to controls. When we divided our patients into SMA1 and SMA2 subgroups, we found that statistical differences were maintained for P-wave and QRS complex amplitudes and heart rate, but not for PRi and QRSi with respect to controls. Conclusion: We suggest the hypothesis of SMN expression on cardiac tissue condition and/or autonomic cardiac conduction.

Multifocal atrial tachycardia

2018 ◽  
Author(s):  
Michael Jones ◽  
Norman Qureshi ◽  
Kim Rajappan
Keyword(s):  
Atrial Fibrillation ◽  
Sinus Rhythm ◽  
Atrial Tachycardia ◽  
The Other ◽  
P Wave ◽  
Qrs Complex ◽  
P Waves ◽  
Ectopic Beats ◽  
Atrial Rhythm ◽  
Pathophysiologic Mechanisms

Multifocal atrial tachycardia (MAT) is an atrial arrhythmia arising in the left or right atrium, or both, with multiple different P wave morphologies (at least three), with an atrial rate usually faster than 100 min−1. The atrial rhythm may be irregular; however, the defining difference between MAT and atrial fibrillation is the presence of a P wave prior to each QRS complex in MAT (but the absence of P waves in atrial fibrillation). MAT may be compared to sinus rhythm with very frequent polymorphic atrial ectopic beats, and in fact similar pathophysiologic mechanisms underlie both conditions; thus, differentiating one from the other may be difficult—the principle difference is the lack of a single dominant sinus pacemaker in MAT.

scholarly journals Gabungan Ekstrak Rimpang Temulawak, Daun Tanjung, dan Daun Belimbing Manis Berdasarkan Electrocardiogram Berpotensi Sebagai Antiaritmia pada Kucing

2019 ◽  
Vol 20 (3) ◽  
pp. 409
Author(s):  
Min Rahminiwati ◽  
Widia Safitri ◽  
Deni Noviana
Keyword(s):  
Heart Rate ◽  
Cardiac Activity ◽  
P Wave ◽  
Control Group ◽  
Qrs Complex ◽  
Averrhoa Carambola ◽  
Effect Mechanism ◽  
Atrial Contraction ◽  
Mimusops Elengi ◽  
Contraction And Relaxation

Mimusops elengi L. , Averrhoa carambola L. and Curcuma xanthorrihiza Roxb singly were reported to have hypothensif effect. Mechanism underlying decrease of blood pressure was suggested through modification of cardiac activity. The Effect of Mimusops elengi L., combined with Averrhoa carambola L. and Curcuma xanthorrihiza Roxb extract on cardiac activity were studied using ECG on 12 male cats that were grouped to be a control group administered aquadestilata, and treatment group administered extract of 21 mg and 82 mg/2 kg bw orally respectively. The extracts were given 3 h prior to ECG. The results showed a decrease in P wave, QRS complex and the speed of the heart rate after administration of combination of extract . However QT and PR intervals were increased. This showed that the extract can weaken a contraction of the Atria and ventricles, prolonging the onset of the occurrence of atrial contraction towards ventricular contraction, extending the onset of contraction and relaxation of the ventricles and cause a decrease in heart rate. Based the cardiogram, It was concluded that their combination is valuable for treatment of aritmia.

Two P waves followed by one QRS complex: What is the mechanism?

Heart Rhythm ◽  
2021 ◽  
Author(s):  
Satoshi Higuchi ◽  
Sung Il Im ◽  
Edward P. Gerstenfeld ◽  
Melvin M. Scheinman
Keyword(s):  
Qrs Complex ◽  
P Waves

Simulation of thermoelastic waves based on the Lord-Shulman theory

Geophysics ◽  
2021 ◽  
Vol 86 (3) ◽  
pp. T155-T164
Author(s):  
Wanting Hou ◽  
Li-Yun Fu ◽  
José M. Carcione ◽  
Zhiwei Wang ◽  
Jia Wei
Keyword(s):  
Thermal Conductivity ◽  
Expansion Coefficient ◽  
Velocity Dispersion ◽  
Wave Attenuation ◽  
Splitting Method ◽  
Grazing Incidence ◽  
P Wave ◽  
Staggered Grid ◽  
Thermal Mode ◽  
P Waves

Thermoelasticity is important in seismic propagation due to the effects related to wave attenuation and velocity dispersion. We have applied a novel finite-difference (FD) solver of the Lord-Shulman thermoelasticity equations to compute synthetic seismograms that include the effects of the thermal properties (expansion coefficient, thermal conductivity, and specific heat) compared with the classic forward-modeling codes. We use a time splitting method because the presence of a slow quasistatic mode (the thermal mode) makes the differential equations stiff and unstable for explicit time-stepping methods. The spatial derivatives are computed with a rotated staggered-grid FD method, and an unsplit convolutional perfectly matched layer is used to absorb the waves at the boundaries, with an optimal performance at the grazing incidence. The stability condition of the modeling algorithm is examined. The numerical experiments illustrate the effects of the thermoelasticity properties on the attenuation of the fast P-wave (or E-wave) and the slow thermal P-wave (or T-wave). These propagation modes have characteristics similar to the fast and slow P-waves of poroelasticity, respectively. The thermal expansion coefficient has a significant effect on the velocity dispersion and attenuation of the elastic waves, and the thermal conductivity affects the relaxation time of the thermal diffusion process, with the T mode becoming wave-like at high thermal conductivities and high frequencies.

Estimates of velocity structure and source depth using multiple P waves from aftershocks of the 1987 Elmore Ranch and Superstition Hills, California, earthquakes

1991 ◽  
Vol 81 (2) ◽  
pp. 508-523
Author(s):  
Jim Mori
Keyword(s):  
Velocity Structure ◽  
Velocity Model ◽  
P Wave ◽  
Sediment Layer ◽  
Source Depth ◽  
Imperial Valley ◽  
P Waves ◽  
Main Shocks ◽  
Aftershock Sequences ◽  
Event Record

Abstract Event record sections, which are constructed by plotting seismograms from many closely spaced earthquakes recorded on a few stations, show multiple free-surface reflections (PP, PPP, PPPP) of the P wave in the Imperial Valley, California. The relative timing of these arrivals is used to estimate the strength of the P-wave velocity gradient within the upper 5 km of the sediment layer. Consistent with previous studies, a velocity model with a value of 1.8 km/sec at the surface increasing linearly to 5.8 km/sec at a depth of 5.5 km fits the data well. The relative amplitudes of the P and PP arrivals are used to estimate the source depth for the aftershock distributions of the Elmore Ranch and Superstition Hills main shocks. Although the depth determination has large uncertainties, both the Elmore Ranch and Superstition Hills aftershock sequences appear to have similar depth distribution in the range of 4 to 10 km.

Reflection moveout approximations for P-waves in a moderately anisotropic homogeneous tilted transverse isotropy layer

Geophysics ◽  
2017 ◽  
Vol 82 (5) ◽  
pp. C175-C185 ◽  
Author(s):  
Ivan Pšenčík ◽  
Véronique Farra
Keyword(s):  
Transverse Isotropy ◽  
Transversely Isotropic ◽  
P Wave ◽  
Weak Anisotropy ◽  
P Waves ◽  
3D Space ◽  
Axis Of Symmetry ◽  
Relative Errors ◽  
Symmetry Tests ◽  
Ti Media

We have developed approximate nonhyperbolic P-wave moveout formulas applicable to weakly or moderately anisotropic media of arbitrary anisotropy symmetry and orientation. Instead of the commonly used Taylor expansion of the square of the reflection traveltime in terms of the square of the offset, we expand the square of the reflection traveltime in terms of weak-anisotropy (WA) parameters. No acoustic approximation is used. We specify the formulas designed for anisotropy of arbitrary symmetry for the transversely isotropic (TI) media with the axis of symmetry oriented arbitrarily in the 3D space. Resulting formulas depend on three P-wave WA parameters specifying the TI symmetry and two angles specifying the orientation of the axis of symmetry. Tests of the accuracy of the more accurate of the approximate formulas indicate that maximum relative errors do not exceed 0.3% or 2.5% for weak or moderate P-wave anisotropy, respectively.

scholarly journals Physiological ECG Value for Polish Half-Bred Anglo-Arab Horses

2012 ◽  
Vol 56 (4) ◽  
pp. 631-635 ◽  
Keyword(s):  
Heart Rate ◽  
P Wave ◽  
P Waves ◽  
T Wave ◽  
Duration Time ◽  
Qt Intervals ◽  
Electrocardiographic Examination ◽  
Electrocardiographic Findings ◽  
Almost All ◽  
T Waves

Abstract The electrocardiographic examination was performed in 33 training horses (2-16 years of age, 11 males and 22 females). Einthoven and precordial leads (I, II, III, aVR, aVL, aVF, CV1, CV2, CV4) were used. The ECG was performed in resting horses and immediately after exercise (10 min walk, 15 min trot, 10 min canter) using a portable Schiller AT-1 3-channel electrocardiograph, with a paper speed of 25 mm sec-1 and a sensitivity of 10 mm.mV-1. The heart rate, wave amplitudes, and duration time were estimated manually. All horses presented a significant increase in heart rate after exercise (rest 43.83 ±10.33 vs. exercise 73.2 ±14.8). QT intervals were significantly shortened in most of the leads. In resting horses, all P waves in the lead I were positive and almost all II, III and CV4 leads were positive. Simple negative P wave dominated in aVR and only simple negative T wave was found in the leads I. The biphasic shape was observed. After exercise, the amplitude of P and T waves rose, however, clear changes were not observed in wave polarisation and form. In the absence of specific racial characteristics of the electrocardiogram in the Polish Anglo- Arabians, electrocardiographic findings can be interpreted according to ECG standards adopted for horses.

scholarly journals Beat-to-Beat P-Wave Analysis Outperforms Conventional P-Wave Indices in Identifying Patients with a History of Paroxysmal Atrial Fibrillation during Sinus Rhythm

Diagnostics ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1694
Author(s):  
Dimitrios Tachmatzidis ◽  
Dimitrios Filos ◽  
Ioanna Chouvarda ◽  
Anastasios Tsarouchas ◽  
Dimitrios Mouselimis ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Sinus Rhythm ◽  
Paroxysmal Atrial Fibrillation ◽  
Univariate Analysis ◽  
Multivariate Logistic Regression Analysis ◽  
P Wave ◽  
P Value ◽  
Wave Analysis ◽  
P Waves ◽  
History Of

Early identification of patients at risk for paroxysmal atrial fibrillation (PAF) is essential to attain optimal treatment and a favorable prognosis. We compared the performance of a beat-to-beat (B2B) P-wave analysis with that of standard P-wave indices (SPWIs) in identifying patients prone to PAF. To this end, 12-lead ECG and 10 min vectorcardiogram (VCG) recordings were obtained from 33 consecutive, antiarrhythmic therapy naïve patients, with a short history of low burden PAF, and from 56 age- and sex-matched individuals with no AF history. For both groups, SPWIs were calculated, while the VCG recordings were analyzed on a B2B basis, and the P-waves were classified to a primary or secondary morphology. Wavelet transform was used to further analyze P-wave signals of main morphology. Univariate analysis revealed that none of the SPWIs performed acceptably in PAF detection, while five B2B features reached an AUC above 0.7. Moreover, multivariate logistic regression analysis was used to develop two classifiers—one based on B2B analysis derived features and one using only SPWIs. The B2B classifier was found to be superior to SPWIs classifier; B2B AUC: 0.849 (0.754–0.917) vs. SPWIs AUC: 0.721 (0.613–0.813), p value: 0.041. Therefore, in the studied population, the proposed B2B P-wave analysis outperforms SPWIs in detecting patients with PAF while in sinus rhythm. This can be used in further clinical trials regarding the prognosis of such patients.

scholarly journals P- waves reflected from the "20" discontinuity" beneath the Mediterranean region

2010 ◽  
Vol 28 (1) ◽  
Author(s):  
A BOTTARI ◽  
B. FEDERICO
Keyword(s):  
Mediterranean Area ◽  
P Wave ◽  
Travel Times ◽  
P Waves ◽  
First Order ◽  
P Wave Velocity ◽  
Different Depths ◽  
The Mediterranean ◽  
Regional Character ◽  
Order Discontinuity

The observed travel-times of the P-waves for twenty shallow, intermediate, and deep earthquakes, with epicenters in the Mediterranean area, are used in order to analyze some characteristics of the upper mantle. A first- order discontinuity, identifiable as the "20° discontinuity", is found at a depth of 505 ± 16 km in the area underneath the Mediterranean basin. The velocity contrast is equal to 12% (above T'= 8.9 km/sec; below V= 9.97 km/sec). Assuming that this discontinuity gives rise to reflected P-waves (PdP), the travel times of these waves are calculated for various hypocentral depths. The observation of impulses identified as PdP on the seismograms of Messina supports this hypothesis. This result and its implications are discussed in the contest of the conclusions of various authors who locate a P-wave velocity-discontinuity at different depths between 400 and 580 km. Finally, particular emphasis is given to the regional character of the analyzed structures in question.

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